Bone Marrow Aspiration Device And Method

ABSTRACT

A bone marrow aspiration device and related method includes an introducer assembly and an aspiration assembly to couple to the introducer assembly. The introducer assembly includes an introducer cannula having a proximal end and a distal end. The introducer cannula defines a lumen between the distal and proximal ends, the distal end being configured to penetrate bone of a patient. The aspiration assembly includes an aspiration cannula that is receivable in the lumen of the introducer cannula and that extends beyond the distal end of the introducer cannula. The aspiration cannula includes a port to aspirate bone marrow, the port being distal to the distal end of the introducer cannula. The aspiration device further includes a mechanism at the introducer assembly to move the introducer cannula and the aspiration cannula in tandem relative to a distal end of the mechanism when the aspiration cannula is positioned within bone.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/885,821, filed Oct. 16, 2015, which claims the benefit of U.S.Provisional Application No. 62/174,849, filed on Jun. 12, 2015, and U.S.Provisional Application No. 62/065,409, filed on Oct. 17, 2014.

The entire teachings of the above applications are incorporated hereinby reference.

BACKGROUND OF THE INVENTION

Bone is made up of a hard outer core, known as cortical bone or corticalplate, and a soft spongy interior known as cancellous bone or trabecularbone, which includes a marrow filling in the porous space within thespongy bone (commonly referred to as bone marrow). The cortical plate isvery hard and provides the rigid structure to the skeleton, which allowsthe skeleton to bear weight. Bone marrow is rich in capillary beds.

A traditional bone marrow aspiration needle is commonly used to accessmarrow from the hip or iliac bone. The traditional aspiration needleincludes an aspiration cannula (also referred to as a cannulated trocar)and a removable stylet that extends through the cannula and has a sharptip. Once the needle is through the cortical plate, the cannula only hasaccess to whatever marrow is directly ahead of the cannula tip, butcannot bend or access marrow to the sides of the cannula. Because thetraditional needle is stiff, the needle can become stuck in the bone ifinserted too deep. There is a risk that the needle breaks when theclinician attempts to forcefully remove the stuck needle. Thus,clinicians often need to perform multiple punctures using a shortedneedle in order to gain larger volumes of aspirate from a more diversecross section of the marrow space. Multiple punctures incur trauma whichcan interfere with the sample collection. For example, increased bloodflow to the area can dilute or contaminate the aspirate, thus reducingthe quality of the aspirated volume. Since the hip bone is long andthin, once the traditional aspiration needle has penetrated corticalbone, the sharp and stiff instrument has the potential to penetratethrough the other side of the cortical bone, resulting in significanttrauma. Consequently, it is important for the surgeon to have a properangle and skilled technique to ensure a safe aspiration.

Therefore, a need exists for a bone marrow aspiration device that canreduce or minimize the aforementioned problems.

SUMMARY OF INVENTION

A bone marrow aspiration device includes an introducer assembly and anaspiration assembly to couple to the introducer assembly. The introducerassembly includes an introducer cannula having a proximal end and adistal end. The introducer cannula defines a lumen between the distaland proximal ends, and the distal end is configured to penetrate bone ofa patient. The aspiration assembly includes an aspiration cannula thatis receivable in the lumen of the introducer cannula and that extendsbeyond the distal end of the introducer cannula. The aspiration cannulaincludes a port to aspirate bone marrow, the port being distal to thedistal end of the introducer cannula. The aspiration device furtherincludes a mechanism at the introducer assembly to move the introducercannula and the aspiration cannula in tandem relative to a distal end ofthe mechanism when the aspiration cannula is positioned within bone.

The mechanism can include a screw assembly that includes a threadedjacket and a lead screw receivable in the threaded jacket. At least aportion of the introducer cannula can extend through the lead screw,e.g., through a central lumen defined by the lead screw.

A length of the introducer cannula that extends from a distal end of thethreaded jacket and, for example, into bone can be adjusted by advancingthe lead screw into the threaded jacket, e.g., by rotating the leadscrew in a first direction, or reversing the lead screw out of thethreaded jacket, e.g., by rotating the lead screw in a second direction,opposite to the first direction.

The mechanism can be configured to move the introducer cannula andaspiration cannula proximally with leverage on the patient. The threadedjacket of the mechanism can define a surface to contact the patient toprovide the leverage.

The screw assembly can be configured to provide a length of travel ofthe lead screw relative to the threaded jacket, the length of travelbeing between about 1.5 inches and about 5 inches. Preferable, thelength of travel is between about 2 inches and about 4 inches.

An exposed length (also referred to as maximum exposed length) caninclude the length of the introducer cannula that extends from thedistal end of the threaded jacket when the screw mechanism is fullyretracted. The exposed length can include the length of the aspirationcannula that extends beyond the distal end of the introducer cannula.The exposed length can be between about 0.75 inches and about 8.5inches. Expressed as a percentage of the length of travel, the exposedlength can be, for example, between about 50% and about 200% of thelength of travel. Preferably, the exposed length is between about 100%and about 150%, more preferably between about 110% and about 133% of thelength of travel. In a particular example, the length of travel is about3.25 inches and the exposed length (of introducer cannula and aspirationcannula) is about 3.5 inches, or about 108% of the length of travel.

The aspiration cannula can form a channel for aspirating bone marrow,the channel communicating with the distal port of aspiration cannula.

The aspiration assembly can include a connector, e.g., a Luer connectoror other suitable connector, to couple to the introducer assembly in anair-tight manner, e.g., to form a seal to seal against air flow throughthe introducer cannula. The sealed coupling mechanically links theassemblies so that the cannulae can be moved in tandem and also preventsair from leaking into the marrow space through the aspiration device andbeing aspirated through the aspiration cannula.

A method of aspirating bone marrow includes positioning an introducercannula of an introducer assembly in bone of a patient. With a mechanismat the introducer assembly, the introducer cannula is moved within thebone with leverage on the patient. Bone marrow is aspirated through alumen of the introducer cannula.

Bone marrow can be aspirated while the introducer cannula is moved withthe mechanism.

An aspiration cannula may be inserted through the lumen of theintroducer cannula, and the bone marrow can be aspirated with theaspiration cannula. The aspiration cannula can extend beyond a distalend of the introducer cannula. An air-tight seal can be formed betweenthe aspiration cannula and the introducer assembly, to seal against airflowing through the introducer cannula. The introducer assembly and theaspiration cannula can be coupled, for example, with a connector. Usingthe mechanism, the coupled cannulae can be moved together, e.g., intandem, and relative to a portion of the mechanism.

Moving the introducer cannula with the mechanism can include moving theintroducer cannula and the aspiration cannula in tandem relative to thethreaded jacket of the mechanism. When moved by the mechanism, theintroducer cannula and the aspiration cannula can move without relativerotation to each other.

The method can include contacting the patient with a surface of thethreaded jacket to provide the leverage, and can further includeadjusting a length of the introducer cannula that extends from a distalend of the threaded jacket by advancing the lead screw into the threadedjacket or reversing the lead screw out of the threaded jacket.

In an embodiment, a method of aspirating bone marrow includes insertingan aspiration cannula through an introducer cannula of an introducerassembly, the introducer cannula positioned in bone of a patient andextending beyond a distal end of the introducer cannula. The methodfurther includes aspirating bone marrow through a port in the aspirationcannula, the port being distal to the distal end of the introducercannula, and, with a mechanism at the introducer assembly, moving theintroducer cannula and the aspiration cannula in tandem within the bonewith leverage on the patient.

The mechanism, e.g., the screw assembly, can act as an adjustable guidefor the introducer cannula and, when present, the aspiration cannula, toadvance the cannulae in tandem into bone space (move the cannulaedistally) or withdraw the cannulae in tandem from the bone space (movethe cannulae proximally). Material can be aspirated or otherwiseextracted from different depths within the bone space, the depthcontrolled by the adjustable guide.

Embodiments of the present invention have many advantages. For example,the second needle (aspiration needle, aspiration assembly) is secured tothe first needle (introducer needle, introducer assembly) in anair-tight manner using a connector. In particular example, the connectorincludes a hollow guide through which the aspiration cannula extends,the guide being attached to the handle of the aspiration assembly. Theguide is inside a threaded tube that is configured to mate to thethreaded mechanism on the handle of the introducer assembly. Thethreaded tube can be rotatable relative to the guide and the handle ofthe aspiration assembly. This system of coupling the two needlesprevents any air from leaking between the introducer cannula and theaspiration cannula during the aspiration process. When putting a secondneedle through a first needle into bone, and aspirating through thesecond needle, the connection between the two needles should prevent airflow between the two needles in response to the negative pressureapplied to the second needle, e.g., vacuum pressure created by asyringe, to avoid the risk of air flowing into the bone and beingaspirated.

The screw mechanism provides a mechanical advantage that, alone or incombination with leverage on the patient provided when pushing thedistal end of the screw mechanism into the patient, can createsufficient force to retrieve a cannula lodged in the bone space.Typically, force is required to advance the second, longer needle intothe marrow space, which can result in the needle becoming lodged in themarrow space. Often, a mallet is used to advance the needle. The screwmechanism can provide the force to retrieve a needle that has beenadvanced forcefully into bone.

Aspiration devices and method that employ a screw mechanism according toembodiments of the present invention provide a further, relatedadvantage. The two needles, once coupled, travel in tandem duringretrieval from the bone, such that the second, longer needle is notpulled over the leading edge of the first needle. When pulling a second,longer aspiration needle through a first, introducer needle, the secondneedle can skive on the leading edge of the first needle, which is aproblem in other approaches for bone marrow aspiration. While thesecond, aspiration needle can be made of a material, such as steel, toavoid skiving along the leading edge of the first, introducer needle,having both needles move in tandem, as in the present approach, avoidsthe problem of skiving altogether.

Another advantage is that force created by the linear plane of the screwmechanism, which can retrieve a needle lodged in bone, also enables theneedle, or needles moving in tandem, to be precisely re-positioned asthe needle(s) is retrieved from the marrow space. For example, the screwmechanism can act as a depth guide to control the precise depth as theaspiration needle is pulled out of the marrow space. In order tooptimize stem cell counts in the extracted bone marrow, it is beneficialto reposition the aspiration needle precisely as the needle is retrievedfrom the medullary space. Each new location represents a new locationfor aspiration.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing will be apparent from the following more particulardescription of example embodiments of the invention, as illustrated inthe accompanying drawings in which like reference characters refer tothe same parts throughout the different views. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingembodiments of the present invention.

FIG. 1A illustrates an example aspiration device including an introducercannula, a sharp stylet and a guide mechanism.

FIG. 1B illustrates the aspiration device of FIG. 1A with the styleremoved and with partial extension of the guide mechanism.

FIG. 1C illustrates insertion of the introducer cannula of theaspiration device of FIG. 1A through skin into bone.

FIG. 1D illustrates the aspiration device of FIG. 1C with the cannulapositioned in bone and the stylet removed.

FIG. 1E illustrates the aspiration device of FIG. 1D with the cannulapartially withdrawn from the bone.

FIG. 2A illustrates another example aspiration device including anintroducer cannula, a sharp stylet, a guide mechanism, and an aspirationcannula.

FIG. 2B illustrates the introducer cannula of FIG. 2A inserted into bonewith the stylet removed.

FIG. 2C illustrates the aspiration cannula of the device of FIG. 2Ainserted through the introducer cannula and into bone.

FIG. 2D illustrates the aspiration cannula and introducer cannula ofFIG. 2C partially withdrawn from the bone with the guide mechanism.

FIG. 3A illustrates another example aspiration device including anintroducer cannula, a sharp stylet, a guide mechanism, and aspirationcannula including a blunt stylet.

FIGS. 3B-3D are front, side and sectional views, respectively, of theaspiration device of FIG. 3A illustrating the aspiration cannulainserted through the introducer cannula.

FIG. 3E illustrates the aspiration device of FIG. 3A with the introducercannula inserted into bone and the sharp stylet removed.

FIG. 3F illustrates the aspiration device of FIG. 3E with the aspirationcannula been inserted through the introducer cannula and into bone.

FIG. 3G illustrates the aspiration cannula of FIG. 3F partiallywithdrawn from bone and introducer cannula completely withdrawn from thebone with extension of the guide mechanism.

FIG. 4 illustrates a sharp stylet and a blunt stylet for use withembodiments of the present invention.

FIG. 5 illustrates an alternative aspiration device including anintroducer cannula having a solid tip and a side hole.

FIG. 6A illustrates another example aspiration device including anintroducer assembly with an introducer cannula and a sharp stylet, aguide mechanism and an aspiration assembly with an aspiration cannulaand a blunt stylet.

FIG. 6B illustrates the aspiration assembly of FIG. 6A coupled to theintroducer assembly after the sharp stylet has been removed.

FIG. 7A is a detailed view of the tip of the introducer assembly of FIG.6A.

FIG. 7B is a detailed view of the tip of the aspiration assembly of FIG.6B.

FIG. 8 is an example syringe for use with embodiments of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

A description of example embodiments of the invention follows below andin the appended pages.

Bone marrow aspiration devices including an introducer cannula and anaspiration cannula are described in International Application No.PCT/US2010/036696, filed on May 28, 2010 and published on Dec. 2, 2010as WO2010/138895 A2, and International Application No.PCT/US2013/067358, filed on Oct. 29, 2013 and published on May 8, 2014as WO2014/070804 A1, the teachings of which are incorporated herein byreference in their entireties.

A method of aspirating tissue according to the present approach caninclude positioning a needle in tissue, e.g., bone, and pulling back theneedle from the tissue through a mechanism, e.g., a screw, a step turn,or stepper motor. Aspiration can occur before, during, or after theneedle is moved. For example, the cannula can be moved mechanicallyforward or backward (distally or proximally) while aspirating. Movementof the cannula can be incremental, e.g., a step, and in a controlledfashion, e.g., through a screw mechanism. For example, a screw mechanismmay be configured to move the cannula forward or backward by 1 cm forevery 360 degree turn of the screw. The screw may be coupled to a handleattached to the cannula for manual operation. The screw mechanism caninclude a jacket that is threaded and through which the screw travels.The threaded jacket can be large enough, i.e., be of sufficient axiallength, to be easily grasped by one hand while the operator uses theother hand to turn the screw. The jacket can also provide leverage whenthe cannula is withdrawn from the bone space using the screw mechanism.Aspiration can occur after an incremental movement of the cannula intoor out of the bone through the mechanism. For example, it may beadvantageous to aspirate bone marrow as the cannula is advanced into thebone space. The cannula can comprise an introducer cannula and anaspiration cannula.

In some embodiments, aspiration is done through a relatively big hole(port) at the distal end of a cannula that is positioned in the bonespace. For example, the diameter of the hole can be as big as the innerdiameter of the cannula, e.g., the inner diameter of the introducercannula. Aspiration may be through one or more holes that are smaller,e.g., side holes (ports) in the cannula. For example, the diameter of aside hole can be smaller than the inner diameter of the introducercannula. An aspiration cannula may be inserted through an introducercannula. A relatively big hole at the distal end of the introducercannula can be closed off by the aspiration cannula, which may have aclosed distal end. Side holes may be positioned along the length of theaspiration cannula, e.g., near the distal end of the aspiration cannula,for aspirating bone marrow. Advantageously, an aspiration cannula havingside ports and a closed distal end can preferentially draw marrow fromthe side ports, while avoiding peripheral blood which can fill the openchannel created in the marrow space by the retracting cannula during theaspiration process.

Aspiration devices of the present invention may use cannula sizes in therange of 6 Gauge to 31 Gauge. A cannula may have an outer diameter inthe range of 0.25 inches to 0.01 inches.

In some embodiments, the aspiration cannula is 14 Gauge or bigger. Theintroducer cannula can be 11 Gauge or bigger.

Configurations of the aspiration device that may be adjusted for aparticular application include the length of the cannula (e.g., thelength of introducer cannula), the length of the screw and the length oftravel of the screw within the jacket, and the ratio of the length ofthe screw to the length of the cannula. In some embodiments, the lengthof travel is at least half the distance of the overall length of thecannula.

An aspiration device may include a handle. Advantageously, the handlecan be attached to the cannula of the device in such a way as to permita certain amount of torque to be applied to the cannula as the cannulais moved within the bone. The handle can also be attached to the leadscrew. Suitable ways of attaching the handle to the cannula, the screwor both the cannula and screw can include using an adhesive, co-molding,or using a hex fit, among others. The handle can include winged portionsfor ease of manual gripping and application of torque.

The jacket of the screw mechanism provides leverage when the cannula iswithdrawn from bone with the screw mechanism. Once the cannula isposition in the bone to a certain depth, the jacket can be screwed downagainst the skin of the patient. Once the jacket is against the patient,continued rotation of the screw, e.g., by rotating the handle of thecannula, pulls the cannula out of the bone. Embodiments of the inventioninclude a jacket that is sized such that it can be held firmly with onehand while the other hand can be used to turn the handle.

In some embodiments, the aspiration assembly may be configured for usein oncology applications. In oncology, typically only a small samplevolume is needed, but one may want to sample from different depthswithin the bone space. An oncology aspiration cannula may have a smallerdiameter. The mechanism that moves the oncology aspiration cannula maybe configured for long enough travel of the cannula into the bone.

FIG. 1A illustrates an example bone marrow aspiration device 10including an introducer cannula 14, a sharp stylet 36 and a guidemechanism 20. Aspiration device 10 includes an introducer assembly 12that includes an introducer cannula 14 having a proximal end 16 and adistal end 18. The introducer cannula 14 defines a lumen between thedistal and proximal ends. The distal end 18 of the cannula 14 isconfigured to penetrate bone. Sharp stylet 36 can be inserted throughthe lumen of the cannula 14 for penetration of bone, in particularcortical bone. As shown, the sharp tip of the stylet 36 extends throughdistal opening 34 in the introducer cannula and beyond the distal end 18of the introducer cannula. Advantageously, handle 38 of the styletinterlocks with handle 30 of the introducer cannula. The aspirationdevice 10 includes a mechanism 20 at the introducer assembly to move theintroducer cannula 14 proximally or distally. As shown, the mechanism 20is positioned distal to the handle 30 of the introducer cannula. Themechanism 20 is configured to move the introducer cannula 14 withleverage on the patient when the cannula is positioned within bone.

As illustrated in FIGS. 1A-1B, the mechanism 20 (also referred to hereinas a screw set) includes a screw assembly that includes a threadedjacket 22 and a lead screw 24 receivable in the threaded jacket. Thethreaded jacket includes an interior threaded portion that cooperateswith an external threaded portion of the lead screw (see also FIG. 3Dand associated description). A length of the introducer cannula 14 thatextends from a distal end 26 of the threaded jacket and into bone can beadjusted by advancing the lead screw into the threaded jacket orreversing the lead screw out of the threaded jacket. For example, inFIG. 1A, the introducer cannula 14 extends a length Li beyond the distalend 26, while in FIG. 1B, the cannula extends a length L2 from thedistal end 26, L2 being shorter than Li. In FIG. 1B, the lead screw 24has been reversed out of the jacket 22 and the mechanism 20 is shown ina partially extended configuration. As further described below, thedistal end 26 of the threaded jacket defines a surface 28 for contactingthe skin of the patient. The lead screw 24 of mechanism 20 is attachedto the handle 30 of the introducer needle 12. As shown, the handle 30includes winged portions. A port 32 is provided at the handle 30 toconnect to another device. The port 32 is in fluid communication withthe lumen of the introducer cannula 14 and with distal port 34. Asyringe or another source of vacuum can be coupled to port 32 toaspirate material, e.g., bone marrow, through cannula 14 after thestylet 36 is removed from the introducer cannula. As shown in FIG. 1B, aconnector 40, e.g., a threaded female Luer connector, is provided at theport 32 and can couple to a corresponding connector of another device.For example, connector 40 can couple to connector 664, e.g., a male Luerconnector, of syringe 662 shown in FIG. 8. As will be described belowwith respect to FIGS. 2A-3G, the connector can also couple to aconnector of an aspiration assembly.

Use of aspiration device 10 will now be described. The aspiration device10 can be used for a variety of different purposes. As described herein,for example, the device 10 can be used to aspirate bone marrow frombone.

The embodiment illustrated in FIG. 1A-1E includes an introducer assembly12 having single cannula 14 with a screw set 20. The screw set is usedto anchor the assembly 12 against the patient so that an operator canuse the screw 24 to retrieve the cannula 14 from the body in acontrolled manner using the patient as leverage. The screw set 20 isused to control the depth of the cannula as it is retrieved from thebody. Anchoring the outer jacket 22 of the screw set 20 against thepatient and unwinding the screw 24 enables precisely repositioning ofthe distal opening of the cannula to a new aspiration location. Thedistal end 26 of the jacket 22 presses against the patient and providethe leverage to extract the cannula using this method. The screw set 20can also be used to control how deep the cannula is advanced into thebody, e.g., the bone space.

As illustrated in FIG. 1C, the introducer cannula 14 of the aspirationdevice 10 with the sharp stylet 36 in place is inserted through skin 70,cortical bone 72, and into bone marrow 74. As shown in FIG. 1C, thedistal end 26 of the jacket 22 has not reached the skin surface. At thispoint, the jacket 22 may screwed down against the patient's skin 70 sothat the surface 28 is flush with the skin surface. If furtherpenetration of the cannula 14 into bone is desired, force can be appliedto the handle 38 at the proximal end of the device 10 to drive thecannula deeper into the bone.

FIG. 1D illustrates the aspiration device 10 of FIG. 1C with the cannula14 positioned in bone and the stylet 36 removed. Once stylet is removed,a channel is created to the bone space, and a syringe (see FIG. 8) canbe attached to the luer port 32 on the top hub of the device 10. Marrowcan be aspirated through opening 34 at the distal end of cannula 14 andinto a syringe coupled to port 32.

FIG. 1E illustrates the aspiration device 10 of FIG. 1E with the cannula14 partially withdrawn from the bone. The cannula 14 has movedproximally to different depth by turning the handle 30, which isattached to lead screw 24, in a counter clockwise direction. Thiscounter clockwise movement causes the mechanism 20 to expand axiallycreating pressure against the patient, which allows the cannula 14 tomove a precise distance out of the body. Advantageously, the lead screw24 and the jacket 22 are configured, e.g., they have sufficient lengthsrelative to the length of the cannula 14, to provide sufficient lengthof travel to withdraw the cannula 14 in a controlled manner from thebone. As in FIG. 1D, marrow can be aspirated at the new location shownin FIG. 1E through opening 34 at the distal end of cannula 14 and intothe syringe. Each new location allows for a fresh aspirate of marrow.

The following are advantageous features of an aspiration device such asdevice 10. The device has a full handle to create sufficient torque (forexample, at least 5 ft-lbs) to unscrew and remove the cannula from thebone space after insertion. The handle of the device and its connectionto the screw set 20 can withstand a certain minimum torque. Deepinsertion into the bone space can result in the cannula getting lodged.When positioning the cannula and aspirating using the screw set 20, thepatient provides leverage to remove the cannula as bone marrow isaspirated. As an illustrative analogy, the patient's body providesleverage similar a bottle that provides leverage to remove the corkusing a cork-screw.

The length and width of the screw jacket 22 is such that the jacket canbe easily grasped with a full hand even after the exposed cannula 14 hasbeen fully inserted into the body. The travel distance of the screw 24inside the jacket 22 is about the same as the length of the outer screwjacket. The travel distance of the screw set is such that, in a fullycollapsed position (e.g., as shown in FIG. 1A), the screw set allows theexposed cannula to penetrate the bone space and then, from thatposition, the screw set can retract the exposed cannula from the bodyand into the fully extended screw set.

Example combination of dimensions that work are:

(a) Screw travel is greater than about 1.5 inches (preferably about 3inches) and

(b) Screw jacket axial length is greater than about 1.5 inches(preferably about 3.5 inches)(e.g., big enough to be easily grasped andsecured in someone's hand).

(c) Distance that the cannula penetrates bone space is greater thanabout 1.5 inches (preferably about 3 inches)

The aspiration device 10 can come with a blunt stylet to replace thesharp stylet used to penetrate cortical bone. The blunt stylet can beused to advance further into bone space, e.g., into trabecular bone 74,and can prevent the cannula to pass through cortical bone once the bonespace is traversed.

An additional bone marrow aspiration device 110 is illustrated in FIGS.2A-2D. The aspiration device 110 is similar to the aspiration device 10described above. Similar features are designated using like referencenumbers, but increased by 100. With respect to such similar features,the above description of device 10 also applies to the device 110.

As with aspiration device 10, the aspiration device 110, illustrated inFIGS. 2A-2B, generally includes an introducer assembly 112 with handle130 and port 132, an introducer cannula 114 with respective proximal anddistal ends 116 and 118, and a mechanism 120 that includes a threadedjacket 122 and a lead screw 124. The distal end 126 of the jacket 122defines a surface 128 for contacting the skin of the patient. The device110 further includes a sharp stylet 136 having a handle 138 thatinterlocks with handle 130. Unlike the device 10 illustrated in FIGS.1A-1E, the device 110 includes an aspiration assembly 142 to couple tothe introducer assembly 112 at port 132 through connector 140. Inaddition, the introducer cannula 114 can be longer than the introducercannula 14 of device 10. Aspiration through the aspiration assembly,when inserted through introducer cannula 114, allows, for example, foraspiration from deeper inside the marrow space.

As shown in FIG. 2A, the aspiration assembly 142 includes an aspirationcannula 144 that is receivable in the lumen of the introducer cannula114 once the sharp stylet 136 is removed. The aspiration assembly 142includes connector 148 that is configured to cooperate with connector140 of the introducer assembly to couple the assemblies to each other.The aspiration cannula 144 includes ports 146 to aspirate bone marrow.The ports 146 are side ports in the aspiration cannula near its distalend, which is closed and has a blunt tip. When the aspiration cannula144 is fully inserted into the introducer cannula 114, the cannula 144extends through opening 134 and beyond the distal end 118 of theintroducer cannula such that the ports 146 are positioned distal to thedistal end 118 of the introducer cannula, as for example illustrated inFIG. 2C.

The aspiration cannula defines a lumen for aspiration bone marrow. Thelumen is in communication with the distal ports 146 and a port 152 atthe handle 150 of the aspiration assembly. A syringe or other source ofvacuum can be coupled to port 152 to aspirate material, e.g., bonemarrow, through aspiration cannula 144. As shown, a connector, e.g., athreaded female Luer connector, at the port 152 can couple to acorresponding connector of a syringe or other source of vacuum.

The embodiment of FIGS. 2A-2G is an aspiration device 110 that includesa screw set 120 similar to the screw set 20 of device 10. A second,aspiration cannula 144 is inserted through the first, introducer cannula114. The aspiration cannula 144 attaches to the Luer hub on the proximalend to the introducer assembly 112, the cannula 144 extending justbeyond the distal end of the cannula 114. The aspiration cannula 144 hasa blunt closed tip with two sets of side holes 146 arranged 180 degreesrotated from each other. The stylet 136 of the introducer cannula 114protrudes from the distal end of the cannula an equal or greaterdistance than the aspiration cannula 144. The stylet, upon removal fromthe introducer cannula, leaves a path in the bone for the aspirationcannula, which, similar to the stylet, protrudes a short distance beyondthe end of the introducer cannula. A stub handle 150 is sufficient forthis embodiment. Typically, little or no force is needed to insert theaspiration cannula 144 because the aspiration cannula does not travelfar beyond the distal end of the introducer cannula 114 and because thecannula can follow the path of the stylet 136.

In FIG. 2B, the introducer cannula 114 of device 110 is shown insertedinto bone with the stylet 136 removed and the distal surface of thescrew mechanism 120 secured against the patient. Once the stylet isremoved, a channel is created to the bone space through which theaspiration cannula can be inserted.

FIG. 2C illustrates the aspiration cannula 144 of the device of FIG. 2Ainserted through the introducer cannula 114 and into bone. Theaspiration cannula 144 is secured to the introducer cannula 114 via theconnector 148 creating an air tight seal as previously described. Theaspiration cannula 144 travels just past the distal end of theintroducer cannula 114, about the same distance the introducer styletprotrudes past the distal end of the introducer cannula prior to removalof the stylet. A syringe (see FIG. 8) can be attached to the luer port152 on the top hub of the aspiration assembly 142. Marrow can beaspirated through the side holes 146 at the distal end of aspirationcannula 144 and into a syringe coupled to port 152.

In FIG. 2D, the aspiration cannula 144 and introducer cannula 114 ofFIG. 2C have been partially withdrawn from the bone with the guidemechanism 120. The two cannulae 114 and 144 are retracted from the bodyin a controlled manner employing mechanism 120, each new depth uponretrieval creating a new spot to aspirate. The aspiration of marrow cancontinue through the side holes 146. The process of moving the cannulaeand aspirating at a new position may be repeated until sufficientaspirate has been obtained.

An additional bone marrow aspiration device 210 is illustrated in FIGS.3A-3G. The aspiration device 210 is similar to the aspiration device110. Similar features are designated using like reference numbers, butincreased by 100. With respect to such similar features, the abovedescription of device 110 also applies to the device 110.

As with aspiration device 110, the aspiration device 210 generallyincludes an introducer assembly 212 with handle 230 and port 232, anintroducer cannula 214 with proximal and distal ends 216 and 218,respectively, and a mechanism 220 that includes threaded jacket 222 andlead screw 224, as illustrated in FIGS. 3A-3D. A distal end 226 of thejacket 222 defines a surface 228 for contacting the skin of the patient.As with device 110, the device 210 further includes a sharp stylet 236having a handle 238 that interlocks with handle 230. The device 210 alsoincludes an aspiration assembly 242 to couple to the introducer assembly212 at port 232 through connector 240. The aspiration assembly 242includes an aspiration cannula 244 with side ports 246, a connector 248configured to cooperate with connector 240 of the introducer assembly tocouple the assemblies to each other, and a port 252 for connecting asyringe or other device. As with the side ports of device 110, when theaspiration cannula 244 is fully inserted into the introducer cannula 214and extends through the distal opening 234, the side ports 246 arepositioned distal to the distal end 218 of the introducer cannula, asfor example illustrated in FIGS. 3B-3D.

Unlike in the aspiration device 110, which is configured such that theaspiration cannula only extends a short length beyond the distal end ofthe introducer cannula, the aspiration device 210 is configured suchthat the aspiration cannula 244 extends substantially further beyond thedistal end of the introducer cannula 214. To facilitate insertion of thecannula 244 into bone space beyond the distal end of the introducercannula, aspiration device 210 is provided with a handle 250 thatincludes winged portions and with a blunt stylet whose handle 254 caninterlock with the handle 250 of the aspiration assembly. An exampleblunt stylet 356 is shown in FIG. 4. The blunt stylet provides stiffnessto the aspiration cannula 244, and the handles 250 and 254 enableapplication of axial force during the insertion of the aspirationcannula into bone.

The embodiment illustrated in FIGS. 3A-3G is similar to the embodimentillustrated in FIGS. 2A-2D in many aspects, but differs in that theaspiration cannula 244 travels a greater distance beyond the introducercannula 214 and is provided with a full handle 250. The aspirationcannula can, for example, extend distally beyond the distal end ofcannula 214 by about 1 inch to about 1.5 inches. The aspiration cannula244 has a full handle 250, e.g., a handle with winged portions, becauseforce is typically needed to advance the cannula 244 past the distal endof the cannula 114 and into the marrow space. The screw mechanism 220 onthe introducer assembly 212 serves as a depth guide for the longeraspiration cannula 244 to which it is not attached. This is so because,once the screw set of the introducer assembly 212 is anchored againstthe patient, the handle 230 of the introducer assembly can be turnedcounter clockwise, which causes the introducer cannula 214 to rise upout of the bone and engage the aspiration cannula 244.

FIG. 3E illustrates the introducer cannula 214 of device 210 insertedinto bone (72, 74). The introducer cannula 214 is extended into thebody, the jacket 222 secured to the skin 70 of patient, and the sharpstylet 236 has been removed creating a channel for the aspirationcannula.

In FIG. 3F, the aspiration cannula 244 has been inserted through theintroducer cannula 214 and into bone marrow 74. The screw mechanism 220,with leverage on the patient, allows the two assemblies (introducer 212and aspiration 242) to be coupled by turning the lower (introducer)handle 230 counter clockwise, which causes introducer assembly to riseup toward the aspiration assembly. Once the two handles 230 and 250 meetand the assemblies are coupled through connector 248, continuing to turnthe introducer handle 230 counter clockwise will cause both cannulae 214and 244 to rise together out of the body.

In FIG. 3G, the aspiration cannula 244 has been partially withdrawn frombone with extension of the guide mechanism 220. The introducer cannula214, which is not visible in FIG. 3G, has been completely withdrawn fromthe bone and into the jacket 222 of the mechanism 220. Here, the turningof the introducer handle 230, and connected lead screw 224, in a counterclockwise direction lifts both cannulae together from the body. Theintroducer handle 230, the jacket 222 and the screw 224 act like a jack.Turning the handle 230 raises the jack which, because the handle 230 isengaged to the aspiration handle 250 by connector 248, moves bothcannulae 214 and 244 together and out of the body.

Returning to FIG. 3D, features of the screw set employed in theembodiments will be described that allow precise changes in the depth ofa cannula across a larger geography as it is retracted from the body. Asshown in section view in FIG. 3D, the length of travel between leadscrew 224 and jacket 222 is indicated as length T, which, in thisexample, is substantially the length of the threaded portion of thescrew 224. The threaded portion of screw 224 engages with a threadedportion 223 of jacket 222. The distance (length) that the introducercannula can extend beyond the distal end 226 when the screw mechanism isfully retracted is indicated as distance A. The distance (length) thatthe aspiration cannula 244 extends beyond the distal end 218 is shown asdistance B.

Combinations of lengths and travel distances that have been found usefulare described with reference to mechanism 220 of FIG. 3D but are alsoapplicable to mechanisms 20, 120, 320, 420 and 520. Suitablecombinations include:

a) The length of the lead screw is at least about 1.5 inches. From apractical perspective, a screw length of over 5 inches would be overlycumbersome. In FIG. 3D, the length of the travel T of the outer jacketof the screw mechanism is substantially equal to the length of thescrew. When the screw length is at 1.5 inches, the jacket can travelabout 1.5 inches relative to the screw, exposing or covering theintroducer cannula in the process. The length of exposed cannula, ofcourse, depends on the length of the cannula.

b) The screw mechanism in its fully retracted position will leave themaximum length of cannula exposed from the distal end of the mechanism(maximum exposed length). The screw mechanism in its fully extendedposition will leave the shortest length of the cannula exposed from thedistal end of the mechanism (minimum exposed length). In the case wherean aspiration cannula is inserted through an introducer cannula, thelength of the two cannulae assembled and extending beyond the distal endof the screw mechanism defines the maximum and minimum exposed length.In FIG. 3D, the maximum exposed length of the introducer cannula aloneis A, the maximum exposed length with the aspiration cannula added isA+B. The maximum exposed length when the screw mechanism is in a fullyretracted position can be at least 50% and not greater than 200% of thelength of travel of the screw relative to the jacket. Table 1 documentspreferred, upper and lower maximum exposed lengths for different lengthsof travel, e.g., different screw lengths.

TABLE 1 Screw length Description 1.5 2 3 4 Screw Length and MaximumExposed Length (inches) lower range Maximum 0.75 1 1.5 2 exposed lengthPreferred Maximum 2 2.5 3.5 4.5 exposed length upper range Maximum 3 3.55.5 7.25 exposed length Maximum Exposed Length as a percentage of ScrewLength With Screw Guide Fully Retracted lower range Maximum  50%  50% 50%  50% exposed length Preferred Maximum 133% 125% 117% 113% exposedlength upper range Maximum 200% 175% 183% 181% exposed length

Because the screw mechanism is used to set the depth of the cannula uponextraction using the patient as leverage, the length of the lead screwpreferably has sufficient travel to anchor against the patient (to allowfor the outer jacket to be screwed down against patient after thecannula is inserted into bone). The length of the screw preferably hassufficient travel to extract the needle from the bone. The parameters ofthe screw being at least 1.5 inches and the ratio of the screw to theoverall “maximum exposed length” can accommodate different bone typesand different sizes of patients (e.g., can accommodate for differingamounts of flesh over the bone of the patient).

Needles that have a screw mechanism on a first needle are designed tojust control depth of entry and so any screw of such a mechanism istypically less than 1.5 inches in length and the ratio of screw lengthto length of exposed needle, when the jacket is in its fully retractedposition, would not be expected to be within the range described above.

Traditional depth guides on marrow needles have a short travel distanceassociated with the screw mechanism, typically 1 inch or less. They aretypically used only to set a depth of insertion and are not designed tocontrol changes in depth as the marrow needle is retracted from thebody. The threads used on traditional depth guides are fine so as tomake small adjustment in penetration depth. These depth guides aretypically provided on needles that are inserted into the vertebral bodyof the spine to make pilot holes for screws.

In embodiment of the present inventions, the combination of the screwset (e.g., 20, 120, 220, 320, 420, 520) and cannula (e.g., 14, 114, 214,314, 414, 514) of the aspiration device allows the clinician to insertthe cannula to a desired depth that can be adjusted during insertion.Once the depth is achieved, the aspiration device is secured against thepatient by turning the screw set counterclockwise so that the outerjacket is snug to the patient skin. In certain embodiments, anaspiration cannula is inserted that has a blunt tip and side ports only.This aspiration cannula is secured to the introducer cannula in anair-tight manner using a connector, to seal against air flow through theintroducer cannula. The connector can be a Luer-type connector and caninclude a hollow guide through which the aspiration cannula fits, theguide being inside a threaded tube, the threaded tube configured toattach to the threaded mechanism of a port on the introducer handle, aspreviously described. The aspiration cannula can be substantially longerthan the introducer needle. Aspiration can occur at different locations(depths) as the cannula is, or cannulae are, moved proximally ordistally within bone. For example, the cannula can be retracted byturning the screw set counter clockwise to position the cannula at a newlocation with each turn. In some embodiments, aspiration occurs from theside holes only.

FIG. 4 illustrates a sharp stylet 336 having handle 338 and a bluntstylet 356 having handle 345 for use with embodiments of the presentinvention. For each embodiment, the introducer cannula that breaksthrough the bone cortex with a sharp stylet, such as stylet 336 can alsohave with it a complimentary blunt tip stylet, such as stylet 356. Oncethe cannula has passed the cortex, some clinicians prefer to advancefurther into the bone space with a blunt tipped stylet to avoid havingthe introducer cannula come out through the cortex on the other side ofthe bone. A blunt stylet, or blunt cannula, is more likely to deflectalong the inner wall of bone cortex. The embodiment illustrated in FIG.5, for example, can benefit from a blunt stylet even though the device'scannula has a closed distal end. The blunt stylet is used to strengthenthe introducer cannula and to prevent debris from clogging up the onemore side holes.

FIG. 5 illustrates an alternative aspiration device 410 including anintroducer cannula 414 having a solid tip 458 and one or more side holes(side ports) 460. The aspiration device 410 is similar to the aspirationdevice 10 of FIGS. 1A-1E. Similar features are designated using likereference numbers, but increased by 400. With respect to such similarfeatures, the above description of device 10 also applies to the device410.

As with aspiration device 10, the aspiration device 410 generallyincludes an introducer assembly 412 with handle 430 and port 432, anintroducer cannula 414 with proximal and distal ends 416 and 418,respectively, and a mechanism 420 that includes threaded jacket 422 andlead screw 424 (inside jacket 422, but see lead screw 24 of FIG. 1B).Unlike the device 10, the device 410 does not include an open distal endat the introducer cannula for aspirating bone marrow, but insteadincludes a solid, sharp tip 458 at the distal end and a side hole 460 inthe introducer cannula. Although only one side hole is shown in FIG. 5,the cannula can include multiple side holes. Aspiration is through theside hole(s) 460. During insertion into bone, a blunt stylet, such asstylet 356 of FIG. 4, can be inserted through port 432 into the lumen ofthe introducer cannula 414 to close off the one or more side holes 460.

An additional bone marrow aspiration device 510 is illustrated in FIGS.6A-6B. The aspiration device 510 is similar to the aspiration device210. Similar features are designated using like reference numbers, butincreased by 300. With regard to such similar features, the abovedescription of device 210 also applies to the device 510.

As with aspiration device 210, the aspiration device 510 generallyincludes an introducer assembly 512 having handle 530 and port 532, anintroducer cannula 514 with proximal and distal ends 516 and 518,respectively, and a mechanism 520 that includes threaded jacket 522 andlead screw 524 (inside jacket 522), as illustrated in FIG. 6A. As withdevice 210, the device 510 further includes a sharp stylet 536 having ahandle 538 that interlocks with handle 530. The device 510 also includesan aspiration assembly 542 configured to couple to the introducerassembly 512 at port 532 through connector 540. The aspiration assembly542 includes an aspiration cannula 544 with side ports 546. A connector548 of assembly 542 is configured to cooperate with connector 540 of theintroducer assembly to couple the assemblies together. A port 552 isprovided for connecting a syringe or other device. As with the sideports of device 210, when the aspiration cannula 544 is fully insertedinto the introducer cannula 514 and extends through the distal openingof the introducer cannula, the side ports 546 are positioned distal tothe distal end 518 of the introducer cannula, as for example illustratedin FIG. 6B. The aspiration device 510 is provided with a handle 550 thatincludes winged portions. Also provided is a blunt stylet whose handle554 can interlock with the handle 550 of the aspiration assembly.

FIG. 7A provides detail view of the distal end of introducer assembly512 of FIG. 6A illustrating the sharp stylet 536 extending beyond thedistal end of the introducer cannula 514. FIG. 7B provides a detail viewof the distal end of the aspiration cannula 544 of FIG. 6B illustratingthe two side ports 546 offset from the closed, distal end of theaspiration cannula.

Device 510 differs from device 210 in the configuration of the distalend 526 of the jacket 522. The jacket 522 tapers at the distal end 528and defines a smaller surface 528 for contacting the skin of the patientas compared to relative large contact surface 228 of device 210 (see,e.g., FIG. 3D). In the particular example, the introducer cannula is an11 Gauge cannula that extends 1.676 inches beyond the distal end of thejacket 522 when the mechanism 520 is in a retracted position, as shownin FIG. 6A. The length of the retracted mechanism is 4.250 inches. Theaspiration cannula, which is a 14 Gauge cannula, extends 3.250 inchesbeyond the distal end 518 of the introducer cannula, as shown in FIG.6B.

Use of device 510 of FIGS. 6A-6B for extracting bone marrow issubstantially the same that of device 210 described above with referenceto FIGS. 3A-3G.

Embodiments have been described that can be used to aspirate material,e.g., bone marrow, by placing the cannula a certain distance into thepatient and then aspirating in different locations along the trajectoryas the cannula is pulled proximally (from the body) with the screwmechanism, e.g., by unwinding the handle of the aspiration device, andwith leverage against the patient. Using the same screw mechanism, onecan aspirate moving the cannula distally (into the body), while usingthe patient as the stop and then using the screw mechanism to retrievethe cannula upon completion of the aspirate.

Aspirating while advancing the cannula is described with reference tothe embodiment of FIGS. 3A-3D. First, one can insert the introducercannula 214 past the cortex into bone marrow with the sharp stylet 236in place. Once past the cortex, one can remove the sharp stylet andscrew the jacket 222 down to patient's skin. Next, one can insert in theblunt tipped aspiration cannula 244 through the introducer cannula 214.The aspiration cannula is longer, e.g., 1.5 inches longer, than theintroducer cannula. Since the inner “spongy bone” is still quite rigid,the handle of the aspiration cannula 244 will likely stop at about 1.5inches above the introducer handle 230 and its distal end dead end atthe distal end of the introducer cannula inside the body. Holding theouter jacket 222 of the screw set 220 with one hand one can turn theintroducer handle 230 counter clockwise until the handle rises up theapproximate 1.5 inches and can connect to the handle 250 of theaspiration cannula. At this point, the introducer cannula 214 may be outof the body, positioned under the extended screw set, and only theaspiration cannula 244 will be a short distance into the body. In otherwords, the introducer cannula slides over the aspiration cannula, butthe aspiration cannula does not move because it is not connected to theintroducer cannula.

At this point, one can connect a syringe to port 252 and aspirate 1 mLof aspirate. This first volume of aspirate is at the top of thetrajectory into the bone. Then, one can turn the jacket 222 of the screwset counter clockwise by 360 degrees. This will cause the screw set 220to rise above the patient a short distance. Then, preferably using amallet, one can tap both of the cannulae forward until the surface 226of outer screw jacket 222 touches the patient. The cannulae will advancethe distance the jacket 222 is above the patient based on turning thejacket 360 degrees. Now, one can connect a syringe and aspirate another1 mL of marrow, the second volume of aspirate in the trajectory. Next,one can disconnect the syringe, turn the jacket 360 degrees to rise itabove the patient, tap the two cannulae forward until the screw jacket222 is flush with patient, re-connect the syringe, and draw 1 mL. Thiscan be repeated until one has obtained the desired volume of aspirate orone runs out of screw length.

Aspirating while advancing the cannulae can be accomplished with theembodiment of FIGS. 2A-2B by having the second cannula 144 closing offthe open lumen of the first cannula 114. Aspiration can occur through acut out made in both cannulae at their distal ends, the cut outs liningup to create a fluid path. Alternatively, the second cannula 144 canprotrude slightly beyond the first cannula 114 and have side ports.

One can also accomplish aspiration, when advancing the cannula with thescrew set into bone, using embodiments that do not include a second,aspiration cannula. Preferably, one employs an aspiration device, suchas device 410, where the distal end is permanently closed with a sharppoint. If an aspiration device, such as device 10, is used, where theend of the introducer cannula has an open distal end after removing thesharp stylet, one would have to put in a stylet every time the cannulais advanced into bone. This is so, because advancing an open lumencannula into bone is not desirable, as the cannula will likely clog,which will diminish, if not prevent, the ability to aspirate through thecannula.

In any case, when aspirating as one advance the cannula, as opposed toas one retracts, the introducer cannula, in the preferred embodiment,has a closed off end with a sharp point. Alternatively, one can closeoff the cannula with a second cannula that is preferably blunt. Thefirst cannula has a screw set. One can use the screw set as a guide toadvance the cannula, or cannulae, only a certain distance based on thedistance between the screw set and the patient, which is based on each360 degree counter clockwise turn of the jacket. Aspiration can occur ateach location as the cannula is advanced.

The teachings of all patents, published applications and referencescited herein are incorporated by reference in their entirety.

While this invention has been particularly shown and described withreferences to example embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the scope of the inventionencompassed by the appended claims.

What is claimed is:
 1. A bone marrow aspiration device comprising: acannula having a proximal end and a distal end and defining a lumenbetween the distal and proximal ends, the distal end of the cannulabeing closed and configured to penetrate a bone of a patient, thecannula defining at least one side aperture spaced proximally from theclosed distal end; a handle at the proximal end of the cannula; aremoveable solid stylet that fits into the handle and extends throughthe cannula and past the at least one side aperture; and a screwmechanism distal to the handle, the mechanism comprising a threadedjacket and a lead screw receivable in the threaded jacket, the threadedjacket including an internal non-threaded portion to receive the leadscrew and an internal threaded portion adjacent the non-threaded portionto engage the lead screw, the lead screw having a length of at least 1.5inches and being longer than the internal threaded portion, the lengthof the lead screw enabling the mechanism to reposition the cannula todifferent depths within the bone, the mechanism configured to lift thecannula out of the bone with rotation of the handle.
 2. The aspirationdevice of claim 1, wherein at least a portion of the cannula extendsthrough the lead screw.
 3. The aspiration device of claim 1, wherein thescrew mechanism is configured to move the cannula proximally with aleverage on the patient.
 4. The aspiration device of claim 3, whereinthe threaded jacket defines a surface to contact the patient to providethe leverage.
 5. The aspiration device of claim 1, wherein a length ofthe cannula that extends from a distal end of the threaded jacket isadjustable by advancing the lead screw into the threaded jacket orreversing the lead screw out of the threaded jacket.
 6. The aspirationdevice of claim 5, wherein the screw mechanism is configured to providea length of travel of the lead screw relative to the threaded jacket,the length of travel being between 1.5 inches and 5 inches.
 7. Theaspiration device of claim 6, wherein an exposed length includes thelength of the cannula that extends from the distal end of the threadedjacket when the screw mechanism is fully retracted, the exposed lengthbeing between 50% and 200% of the length of travel.
 8. The aspirationdevice of claim 7, wherein the exposed length includes the length of asolid tip at the distal end of the cannula configured to penetrate bone.9. The aspiration device of claim 1, wherein the handle includes aconnector to couple a syringe in an air-tight manner to seal against airflow through the cannula.
 10. The aspiration device of claim 1, whereinthe stylet fits coaxially into the cannula when attached to the handleand extends past the most distal side aperture but ends at the closeddistal end of the cannula, thereby strengthening the cannula where theat least one side aperture is provided.
 11. The aspiration device ofclaim 1, wherein the stylet fits coaxially into the cannula whenattached to the handle and extends past the most distal side aperture,thereby closing off the at least one side aperture.
 12. The aspirationdevice of claim 1, wherein, in a fully retracted position of the screwmechanism, the lead screw is received along its entire length in thethreaded jacket.